The role of regulatory T cells and programmed death-1 in multipl myeloma

T regulatory cells (Treg), having roles in immunosupression and control of autoimmunity are a contemporary issue in immune response to tumor cells. CD200 has an immunosuppressive effect on T cell mediated immunity. Its up regulation is thought to be related with escape of tumor cells from immune system. Programmed Death-1 (PD1) is expressed on T cells, B cells, natural killer cells and dendritic cells. It has inhibitory signals in immune response. It stimulates T cell apoptosis. Its inhibition is related with tumor progression.Aim of this study is to compare the levels of CD4+ CD25+ Foxp3+ Treg cells, CD200 and PD-1 in multiple myeloma (MM) with and without autologous bone marrow transplantation (ABMT).Blood samples were collected from 28 MM patients (10 female, 18 male) aged between 41 and 78. in sterile EDTA containers. Peripheral blood mononuclear cells (PBMC) were isolated by density gradient centrifugation on Biocoll separating solution (d 1.077g/ml) and underwent immediate analysis by flow cytometry. Results were analyzed with Mann Whitney nonparametric test using the Statistical Package for the Social Sciences (SPSS) software (9.05). P values<0.05 were considered statistically significant.In this study Treg cells are shown to be higher in patients ABMT (p=0.042). But CD200 and PD-1 did not show statistical significance between two groups (p=0.711, 0.404 respectively). ABMT or Treg cells levels are not correlated by CD200 and PD-1 expression. According to our study negative corelation between Treg and PD-1 levels are observed as previous studies in literatures. Effect of Treg cells on bone marrow with or without chemotherapoetic agents should be questioned on MM.